I have the following funds in a Roth IRA in a Fidelity account, and am determining if it is worth switching funds for a few of them. I mainly picked these because they have low expense ratios. I'm in my late 20s so not planning to cash out for a while, but was wondering if changing funds now to realize gains later on, or if at this point, it doesn't matter. I am also curious about the tax implications in switching funds, or since it's a Roth IRA, whether that is applicable.
FNILX: +4.62% since buy, life of fund +6.5%
FSKAX: +17.29% since buy, life of fund +7.6%
FXAIX: +3.62% since buy, life of fund +10.2%
FZIPX: -2.15% since buy, life of fund -5.96%
I skimmed a John Bogle book, so that is the extent of my investing knowledge.